AFS: implement file locking

Implement file locking for AFS.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 8 insertions, 0 deletions

diff --git a/fs/afs/afs.h b/fs/afs/afs.h
index 245257948140..c548aa346f0d 100644
--- a/fs/afs/afs.h
+++ b/fs/afs/afs.h
@@ -37,6 +37,13 @@ typedef enum {
         AFS_FTYPE_SYMLINK       = 3,
 } afs_file_type_t;
 
+typedef enum {
+        AFS_LOCK_READ           = 0,    /* read lock request */
+        AFS_LOCK_WRITE          = 1,    /* write lock request */
+} afs_lock_type_t;
+
+#define AFS_LOCKWAIT            (5 * 60) /* time until a lock times out (seconds) */
+
 /*
  * AFS file identifier
  */
@@ -120,6 +127,7 @@ struct afs_file_status {
         struct afs_fid          parent;         /* parent dir ID for non-dirs only */
         time_t                  mtime_client;   /* last time client changed data */
         time_t                  mtime_server;   /* last time server changed data */
+        s32                     lock_count;     /* file lock count (0=UNLK -1=WRLCK +ve=#RDLCK */
 };
 
 /*